NAME

term - format of compiled term file.

SYNOPSIS

term

DESCRIPTION

Compiled terminfo descriptions are placed under the direc-
tory /usr/share/terminfo. In order to avoid a linear search
of a huge UNIX system directory, a two-level scheme is used:
/usr/share/terminfo/c/name where name is the name of the
terminal, and c is the first character of name. Thus, act4
can be found in the file /usr/share/terminfo/a/act4.
Synonyms for the same terminal are implemented by multiple
links to the same compiled file.
The format has been chosen so that it will be the same on
all hardware. An 8 or more bit byte is assumed, but no
assumptions about byte ordering or sign extension are made.
The compiled file is created with the tic program, and read
by the routine setupterm. The file is divided into six
parts: the header, terminal names, boolean flags, numbers,
strings, and string table.
The header section begins the file. This section contains
six short integers in the format described below. These
integers are (1) the magic number (octal 0432); (2) the
size, in bytes, of the names section; (3) the number of
bytes in the boolean section; (4) the number of short
integers in the numbers section; (5) the number of offsets
(short integers) in the strings section; (6) the size, in
bytes, of the string table.
Short integers are stored in two 8-bit bytes. The first byte
contains the least significant 8 bits of the value, and the
second byte contains the most significant 8 bits. (Thus, the
value represented is 256*second+first.) The value -1 is
represented by the two bytes 0377, 0377; other negative
values are illegal. This value generally means that the
corresponding capability is missing from this terminal. Note
that this format corresponds to the hardware of the VAX and
PDP-11 (that is, little-endian machines). Machines where
this does not correspond to the hardware must read the
integers as two bytes and compute the little-endian value.
The terminal names section comes next. It contains the first
line of the terminfo description, listing the various names
for the terminal, separated by the `|' character. The sec-
tion is terminated with an ASCII NUL character.
MirOS BSD #10-current Printed 09.04.2016 1
TERM(5) UNIX Programmer's Manual TERM(5)
The boolean flags have one byte for each flag. This byte is
either 0 or 1 as the flag is present or absent. The capabil-
ities are in the same order as the file <term.h>.
Between the boolean section and the number section, a null
byte will be inserted, if necessary, to ensure that the
number section begins on an even byte (this is a relic of
the PDP-11's word-addressed architecture, originally
designed in to avoid IOT traps induced by addressing a word
on an odd byte boundary). All short integers are aligned on
a short word boundary.
The numbers section is similar to the flags section. Each
capability takes up two bytes, and is stored as a little-
endian short integer. If the value represented is -1, the
capability is taken to be missing.
The strings section is also similar. Each capability is
stored as a short integer, in the format above. A value of
-1 means the capability is missing. Otherwise, the value is
taken as an offset from the beginning of the string table.
Special characters in ^X or \c notation are stored in their
interpreted form, not the printing representation. Padding
information $<nn> and parameter information %x are stored
intact in uninterpreted form.
The final section is the string table. It contains all the
values of string capabilities referenced in the string sec-
tion. Each string is null terminated.
Note that it is possible for setupterm to expect a different
set of capabilities than are actually present in the file.
Either the database may have been updated since setupterm
has been recompiled (resulting in extra unrecognized entries
in the file) or the program may have been recompiled more
recently than the database was updated (resulting in missing
entries). The routine setupterm must be prepared for both
possibilities - this is why the numbers and sizes are
included. Also, new capabilities must always be added at the
end of the lists of boolean, number, and string capabili-
ties.
Despite the consistent use of little-endian for numbers and
the otherwise self-describing format, it is not wise to
count on portability of binary terminfo entries between com-
mercial UNIX versions. The problem is that there are at
least three versions of terminfo (under HP-UX, AIX, and
OSF/1) which diverged from System V terminfo after SVr1, and
have added extension capabilities to the string table that
(in the binary format) collide with System V and XSI Curses
extensions. See terminfo(5) for detailed discussion of ter-
minfo source compatibility issues.
MirOS BSD #10-current Printed 09.04.2016 2
TERM(5) UNIX Programmer's Manual TERM(5)
As an example, here is a hex dump of the description for the
Lear-Siegler ADM-3, a popular though rather stupid early
terminal:
adm3a|lsi adm3a,
am,
cols#80, lines#24,
bel=^G, clear= 32$<1>, cr=^M, cub1=^H, cud1=^J,
cuf1=^L, cup=\E=%p1%{32}%+%c%p2%{32}%+%c, cuu1=^K,
home=^^, ind=^J,
0000 1a 01 10 00 02 00 03 00 82 00 31 00 61 64 6d 33 ........ ..1.adm3
0010 61 7c 6c 73 69 20 61 64 6d 33 61 00 00 01 50 00 a|lsi ad m3a...P.
0020 ff ff 18 00 ff ff 00 00 02 00 ff ff ff ff 04 00 ........ ........
0030 ff ff ff ff ff ff ff ff 0a 00 25 00 27 00 ff ff ........ ..%.'...
0040 29 00 ff ff ff ff 2b 00 ff ff 2d 00 ff ff ff ff ).....+. ..-.....
0050 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
0060 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
0070 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
0080 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
0090 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
00a0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
00b0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
00c0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
00d0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
00e0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
00f0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
0100 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
0110 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ........ ........
0120 ff ff ff ff ff ff 2f 00 07 00 0d 00 1a 24 3c 31 ....../. .....$<1
0130 3e 00 1b 3d 25 70 31 25 7b 33 32 7d 25 2b 25 63 >..=%p1% {32}%+%c
0140 25 70 32 25 7b 33 32 7d 25 2b 25 63 00 0a 00 1e %p2%{32} %+%c....
0150 00 08 00 0c 00 0b 00 0a 00 ........ .
Some limitations: total compiled entries cannot exceed 4096
bytes. The name field cannot exceed 128 bytes.